I was out all day. That is a total mystery, you have to question the lnb, can you try the old lnb. and any likely obstruction, a cable, trees/shrub.
Did you move the whole rig left and right and is it dead straight. I'm stumped now. Remember you did get 23 in the past. When you move dish do you get the onscreen dish thingy? And when you go to 28east do you get good signal on cnn or channel 5. If you go to 28 and get a good signal , then use positioner to move dish east its only. 5 degrees.
For an installer i'll do a pm, may not be allowed to post here.